A coal mill cloud-edge fusion control system for cement production

Abstract

The invention discloses a coal mill cloud-edge fusion control system for cement production, comprising an acquisition control module, an edge terminal module, and a pan-tilt server. The acquisition control module comprises a signal acquisition sensor, an actuator, and a PLC. The signal acquisition sensor is electrically connected to the PLC for signal transmission, and the PLC is electrically connected to the actuator for control; the edge terminal module comprises an edge server, and the edge server is communicatively connected to the PLC in the acquisition control module; the pan-tilt server is communicatively connected to the edge server.

Description

Technical Field

[0001] The invention relates to the field of cement coal mill control systems, in particular to a coal mill cloud-edge fusion control system for cement production. Background Art

[0002] Coal mill is a necessary equipment in cement production. It is driven by the main motor of coal mill. Cold air and hot air are input into the coal mill through cold air valve and hot air valve. Coal blocks are crushed by coal mill and then ground into coal powder and output to other production equipment. Temperature sensors are generally installed at the outlet of coal mill to collect the outlet temperature signal of coal mill. The control system of existing coal mill includes simple PID control. Simple PID control keeps its Kp, Ki and Kd parameters constant. The cold and hot air valves are controlled by the deviation between the actual outlet temperature of coal mill and the set value of outlet temperature. Therefore, its disadvantages are that the PID parameters are constant, it cannot adapt to the changeable coal mill system, and the adjustment accuracy is not high. Summary of the invention

[0003] The present invention provides a coal mill cloud-edge fusion control system for cement production to solve the problems in the prior art coal mill control system that the parameters cannot adapt to the changeable coal mill system and the adjustment accuracy is not high.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A coal mill cloud-edge fusion control system for cement production, including an acquisition control module, an edge terminal module, and a pan-tilt server, wherein:

[0006] The acquisition control module includes a signal acquisition sensor, an actuator, and a PLC; the signal acquisition sensor acquires the real-time signal of the coal mill outlet temperature, the real-time signal of the cold air valve opening, and the real-time signal of the hot air valve opening, and the signal acquisition sensor is electrically connected to the PLC signal transmission, and the signal acquisition sensor sends the acquired real-time signal of the coal mill outlet temperature, the real-time signal of the cold air valve opening, and the real-time signal of the hot air valve opening to the PLC; the actuator is used to adjust the opening of the cold air valve and the hot air valve, and the PLC is electrically connected to the actuator control, and the PLC controls the opening of the cold air valve and the hot air valve through the actuator;

[0007] The edge terminal module includes an edge server, which is connected to the PLC in the acquisition control module. The PLC converts each real-time signal obtained into data and transmits it to the edge server; the edge server is integrated with a PID control module, which controls the outlet temperature of the coal mill according to the real-time data of the outlet temperature of the coal mill obtained from the PLC and the set value T of the outlet temperature of the coal mill. wd_set Compare and obtain the deviation, and then calculate the proportional gain parameter Kp of the coal mill according to the deviation. mm , integration parameter Ki mm , differential parameter Kd mm, calculate the opening control amount of the cold air valve and the hot air valve, and the edge server transmits the opening control amount to the PLC, and finally the PLC controls the opening of the cold air valve and the hot air valve through the actuator based on the opening control amount, thereby controlling the actual coal mill outlet temperature;

[0008] The PTZ server is connected to the edge server in communication. The PTZ server obtains the cold air valve, hot air valve opening control amount and the corresponding actual coal mill outlet temperature, as well as the proportional gain parameter Kp of the coal mill from the PID control module of the edge server. mm , integration parameter Ki mm , differential parameter Kd mm , and the PTZ server optimizes the proportional gain parameter Kp according to the genetic algorithm mm , integration parameter Ki mm , differential parameter Kd mm After that, the optimized proportional gain parameter Kp mm , integration parameter Ki mm , differential parameter Kd mm Return to the edge server.

[0009] Furthermore, the edge server is also integrated with a GPC control module, which predicts the future output curve of the coal mill outlet temperature and compares it with the coal mill outlet temperature set value T wd_set The deviation sequence is obtained by comparison, and then the GPC prediction step length P of the coal mill is calculated based on the deviation sequence and the opening of the cold air valve, hot air valve and coal mill. mm , coal mill control step C mm , coal mill control weight λ mm The GPC performance index is constituted; and the upper and lower limit constraints of the opening increments of the cold air valve and the hot air valve, and the upper and lower limit constraints of the openings of the cold air valve and the hot air valve constitute the GPC control constraints; at the kth sampling moment, GPC optimization control is performed on the GPC performance index and the GPC control constraints, so as to obtain the control amount of the opening of the cold air valve and the hot air valve at the kth sampling moment, and the edge server transmits the opening control amount to the PLC, and finally the PLC controls the opening of the cold air valve and the hot air valve through the actuator based on the opening control amount, thereby controlling the actual coal mill outlet temperature.

[0010] Furthermore, the PTZ server obtains the GPC prediction step length P of the coal mill from the GPC control module of the edge server. mm , control step length C mm , control weight λ mm , and optimize the GPC prediction step length P according to the genetic algorithm mm , control step length C mm , control weight λ mm After that, the optimized GPC prediction step length P mm , control step length Cmm , control weight λ mm Return to the edge server.

[0011] Furthermore, the PTZ server controls the edge server to switch to a PID control module and then a GPC control module.

[0012] Furthermore, the acquisition control module also includes a DCS, and the DCS is communicatively connected with the PLC.

[0013] Compared with the prior art, the present invention has the following advantages: PID parameters and GPC parameters can be optimized through the PTZ server, ensuring that the control can be adjusted according to the real-time working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the system structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0016] like Figure 1 As shown, this embodiment discloses a coal mill cloud-edge fusion control system for cement production, including an acquisition control module, an edge terminal module, and a pan-tilt server.

[0017] The acquisition control module includes signal acquisition sensors, actuators, PLC, and DCS. The signal acquisition sensors include field temperature sensors and valve opening sensors. The field temperature sensor is used to collect the real-time signal of the coal mill outlet temperature, and the valve opening sensor is used to collect the real-time signal of the cold air valve and hot air valve opening of the coal mill.

[0018] The signal acquisition sensor is electrically connected to the PLC signal transmission, and the signal acquisition sensor sends the collected real-time signal of the coal mill outlet temperature, the real-time signal of the cold air valve opening, and the real-time signal of the hot air valve opening to the PLC, and the PLC converts each real-time signal into data respectively.

[0019] The actuator is used to adjust the opening of the cold air valve and the hot air valve. The PLC is electrically connected to the actuator control, and the PLC controls the opening of the cold air valve and the hot air valve through the actuator.

[0020] DCS is connected to PLC for communication, and DCS obtains all cement burning system data from PLC.

[0021] The edge terminal module includes an edge server and a switch. The edge server is connected to the PTZ server, the PLC in the acquisition control module, and the DCS through the switch. The edge server supports standard industrial protocols such as OPC and MODBUS, and supports RS485 and RJ45 interfaces. The edge server collects data from the DCS system and PLC equipment. The edge server obtains real-time data on the coal mill outlet temperature, the cold air valve opening, and the hot air valve opening from the PLC.

[0022] The edge server integrates a PID control module and a GPC control module, where:

[0023] The PID control module is based on the real-time data of the coal mill outlet temperature obtained from the PLC and the coal mill outlet temperature set value T wd_set The deviation is obtained by comparison, that is, the coal mill outlet temperature setting value T wd_set Subtract the real-time data of coal mill outlet temperature to obtain the deviation.

[0024] Then, the PID control module calculates the proportional gain parameter Kp of the coal mill according to the deviation. mm , integration parameter Ki mm , differential parameter Kd mm , calculate the opening control quantity of the cold air valve and the hot air valve, the calculation process is:

[0025] Vu=Kp mm {e(k)-e(k-1)}+Ki mm e(k)+Kd mm {e(k)-2e(k-1)+e(k-2)},

[0026] Among them, e(k) represents the deviation at time k.

[0027] Finally, the edge server transmits the opening control quantity obtained by the PID control module to the PLC, and finally the PLC controls the opening of the cold air valve and the hot air valve through the actuator based on the opening control quantity, thereby controlling the actual coal mill outlet temperature.

[0028] The GPC control module predicts the future output curve of the coal mill outlet temperature based on the coal mill outlet temperature model. The coal mill outlet temperature model is a coal mill outlet temperature-cold and hot air valve opening model, which is established offline by the ARMAX algorithm, that is, based on the coal mill outlet temperature, cold air valve opening, and hot air valve opening data collected on site, the coal mill outlet temperature-cold and hot air valve opening ARMAX model is calculated offline on the PTZ server. The prediction process is:

[0029] The GPC control module compares the future output curve of the coal mill outlet temperature with the coal mill outlet temperature set value T wd_setThe deviation sequence is obtained by comparison, and then the GPC prediction step length P of the coal mill is calculated based on the deviation sequence and the opening of the cold air valve, hot air valve and coal mill. mm , coal mill control step C mm , coal mill control weight λ mm The GPC performance index is constituted; and the upper and lower limit constraints of the opening increments of the cold air valve and the hot air valve, and the upper and lower limit constraints of the openings of the cold air valve and the hot air valve constitute the GPC control constraints; at the kth sampling time, the GPC optimization control is performed on the GPC performance index and the GPC control constraints, so as to obtain the control amount of the opening of the cold air valve and the hot air valve at the kth sampling time, and the calculation process is:

[0030] Step 1: Establish a coal mill temperature state space model as a predictive controller.

[0031] Get real-time data of coal mill system MM (k),u FM (k)}, k represents time, k = 1, ..., N, where T MM (k) is the real-time coal mill outlet gas temperature, u FM (k) is the opening degree of the hot air valve obtained in real time.

[0032] Using moving average filter to preprocess real-time data of coal mill system MM (k),u FM (k)}, get the filtered data in: Corresponding to T MM (k) and u FM (k) Filtered data.

[0033] Then the min-max normalization algorithm is used to normalize the filtered data to obtain the normalized data in:

[0034] Corresponding to Normalized data.

[0035] Next, the normalized data obtained As input and output data, the matrix A is identified using the subspace identification method. m , B m , C m , the coal mill temperature state space model is obtained, as shown in formulas (1) and (2):

[0036] x m (k+1)=A m x m (k)+B m u(k) (1),

[0037] y(k)=C m x m (k) (2),

[0038] In formulas (1) and (2), x m (k) represents the state of the coal mill temperature state space model; u(k) represents the input of the coal mill temperature state space model, y(k) represents the input of the coal mill temperature state space model,

[0039] Finally, the average correlated variance method is used to determine the accuracy of the established coal mill temperature state space model.

[0040] Step 2: Use the predictive controller to control the hot air valve opening.

[0041] According to the coal mill temperature state space model, the future output curve of the coal mill system outlet gas temperature is predicted and compared with the expected coal mill system outlet gas temperature setting value. Based on the comparison result, predictive control optimization is performed to obtain the first opening control optimization value u of the hot air valve. FMpre (k) to control the temperature of the actual coal mill system. The process is as follows:

[0042] First, combine formulas (1) and (2) to obtain formula (3) as follows:

[0043]

[0044] From formula (3), we can get:

[0045] Δx m (k+1)=x m (k+1)-x m (k)

[0046] =A m (x m (k)-x m (k-1))+B m (u(k)-u(k-1))

[0047] =A m Δx m (k)+B m Δu(k) (4),

[0048] y(k+1)-y(k)=C m (x m (k+1)-x m (k)) = C m Δx m (k+1)

[0049] =C m A m Δx m (k)C m B m Δu(k)

[0050] (5)

[0051] According to (4) and (5), the state space equation is shown in formula (6):

[0052]

[0053] in:

[0054]

[0055] Assume that the current time is k i ,x(k i ) is the system state variable, then N c The future control variable sequence is expressed as Δu(k i ), Δu(k i +1),…,Δu(k i +N c +1), N p The predicted state variable is represented as x(k i +1|k i ), x(k i +2|k i ), …, x(k i +m|k i ), …, x(k i +N p |k i ). Based on the state space equation of formula (6), the future state variables are calculated using the future control parameters as shown in formula (7):

[0056]

[0057]

[0058] The output variable for calculation prediction is shown in formula (8):

[0059]

[0060] Combining (7) and (8), we get formula (9) as follows:

[0061] Y=Fx(k i )+ΦpΔU (9),

[0062] in:

[0063]

[0064] The performance function is defined as shown in formula (10):

[0065]

[0066] in:

[0067] r(k i ) is k i The set value at the moment;

[0068] r ω is the control amount weight;

[0069] Substitute formula (9) into formula (10), find the partial derivative of J, set the partial derivative to 0, and finally obtain formula (11) as shown below:

[0070]

[0071] The first opening control optimization value u of the hot air valve FMpre (k) = u FMpre (k-1)+ΔU.

[0072] Finally, the edge server transmits the opening control quantity obtained by the GPC control module to the PLC, and finally the PLC controls the opening of the cold air valve and the hot air valve through the actuator based on the opening control quantity, thereby controlling the actual coal mill outlet temperature.

[0073] The PTZ server is connected to the edge server. The cloud platform server includes a central database and a web server, which are used to uniformly manage the collected data and classify and archive the data by device. The data types are classified and archived, including real-time status data, fault data, etc., to facilitate data query and sharing.

[0074] The cloud platform server configures the PLC to use the PID control module or GPC control module by configuring the control parameters. The cloud platform server obtains the cold air valve, hot air valve opening control amount and the corresponding actual coal mill outlet temperature, as well as the coal mill proportional gain parameter Kp from the PID control module of the edge server. mm , integration parameter Ki mm , differential parameter Kd mm The PTZ server also obtains the GPC prediction step length P from the GPC control module of the edge server. mm , coal mill control step length C mm , coal mill control weight λ mm .

[0075] The PTZ server optimizes the proportional gain parameter Kp based on the genetic algorithm mm, integration parameter Ki mm , differential parameter Kd mm , GPC prediction step length P mm , control step length C mm , control weight λ mm , the optimization process is as follows:

[0076] The PTZ server also optimizes the proportional gain parameter Kp mm , integration parameter Ki mm , differential parameter Kd mm , GPC prediction step length P mm , control step length C mm , control weight λ mm The data is returned to the edge server, so that the edge server can control the opening of the cold air valve and the hot air valve based on the optimized parameters.

[0077] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. The embodiments described in the present invention are merely descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. The various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction, and such combinations should also be regarded as the contents disclosed in the present disclosure as long as they do not violate the concept of the present invention. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0078] The present invention is not limited to the specific details of the above-mentioned embodiments. Within the scope of the technical concept of the present invention and without departing from the design concept of the present invention, various modifications and improvements made to the technical solution of the present invention by technical personnel in this field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. A coal mill cloud-edge fusion control system for cement production, characterized in that: It includes acquisition control module, edge terminal module and PTZ server, among which: The acquisition control module includes a signal acquisition sensor, an actuator, and a PLC; the signal acquisition sensor acquires the real-time signal of the coal mill outlet temperature, the real-time signal of the cold air valve opening, and the real-time signal of the hot air valve opening, and the signal acquisition sensor is electrically connected to the PLC signal transmission, and the signal acquisition sensor sends the acquired real-time signal of the coal mill outlet temperature, the real-time signal of the cold air valve opening, and the real-time signal of the hot air valve opening to the PLC; the actuator is used to adjust the opening of the cold air valve and the hot air valve, and the PLC is electrically connected to the actuator control, and the PLC controls the opening of the cold air valve and the hot air valve through the actuator; The edge terminal module includes an edge server, which is connected to the PLC in the acquisition control module. The PLC converts each real-time signal obtained into data and transmits it to the edge server; the edge server is integrated with a PID control module, which controls the outlet temperature of the coal mill according to the real-time data of the outlet temperature of the coal mill obtained from the PLC and the set value T of the outlet temperature of the coal mill. wd_set Compare and obtain the deviation, and then calculate the proportional gain parameter Kp of the coal mill according to the deviation. mm , integration parameter Ki mm , differential parameter Kd mm , calculate the opening control amount of the cold air valve and the hot air valve, and the edge server transmits the opening control amount to the PLC, and finally the PLC controls the opening of the cold air valve and the hot air valve through the actuator based on the opening control amount, thereby controlling the actual coal mill outlet temperature; The PTZ server is connected to the edge server in communication. The PTZ server obtains the cold air valve, hot air valve opening control amount and the corresponding actual coal mill outlet temperature, as well as the proportional gain parameter Kp of the coal mill from the PID control module of the edge server. mm , integration parameter Ki mm , differential parameter Kd mm , and the PTZ server optimizes the proportional gain parameter Kp according to the genetic algorithm mm , integration parameter Ki mm , differential parameter Kd mm After that, the optimized proportional gain parameter Kp mm , integration parameter Ki mm , differential parameter Kd mm Return to the edge server.

2. A coal mill cloud edge fusion control system for cement production according to claim 1, characterized in that: The edge server also integrates a GPC control module, which predicts the future output curve of the coal mill outlet temperature and compares it with the coal mill outlet temperature set value T wd_set The deviation sequence is obtained by comparison, and then the GPC prediction step length P of the coal mill is calculated based on the deviation sequence and the opening of the cold air valve, hot air valve and coal mill. mm , coal mill control step C mm , coal mill control weight λ mm The GPC performance index is constituted; and the upper and lower limit constraints of the opening increments of the cold air valve and the hot air valve, and the upper and lower limit constraints of the openings of the cold air valve and the hot air valve constitute the GPC control constraints; at the kth sampling moment, GPC optimization control is performed on the GPC performance index and the GPC control constraints, so as to obtain the control amount of the opening of the cold air valve and the hot air valve at the kth sampling moment, and the edge server transmits the opening control amount to the PLC, and finally the PLC controls the opening of the cold air valve and the hot air valve through the actuator based on the opening control amount, thereby controlling the actual coal mill outlet temperature.

3. A coal mill cloud edge fusion control system for cement production according to claim 2, characterized in that: The cloud platform server obtains the GPC prediction step length P of the coal mill from the GPC control module of the edge server mm , control step length C mm , control weight λ mm , and optimize the GPC prediction step length P according to the genetic algorithm mm , control step length C mm , control weight λ mm After that, the optimized GPC prediction step length P mm , control step length C mm , control weight λ mm Return to the edge server.

4. A coal mill cloud-edge fusion control system for cement production according to claim 2, characterized in that: The cloud platform server controls the edge server to switch to a PID control module and then a GPC control module.

5. A coal mill cloud-edge fusion control system for cement production according to any one of claims 1 to 4, characterized in that: The acquisition control module also includes a DCS, and the DCS is in communication connection with the PLC.

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